DENIALS: Kosminski, was NOT the Ripper, according to investigators [GETTY]

A new book claims DNA ­evidence proves “beyond doubt” the 1888 Whitechapel murders were carried out by immigrant Aaron Kosminski.

The book, Naming Jack The Ripper, relies on analysis of blood samples on a shawl that was said to have been owned by victim Catherine Eddowes.

It says Kosminski “definitely, categorically and absolutely” ­perpetrated the Ripper killings when he was 23.

But Trevor Marriott, a former murder squad investigator with Bedfordshire Police, said the ­findings were “inconclusive and unsafe”. He said the DNA ­evidence did not stand up to scrutiny.

The ex-copper, 60, who spent more than ten years reviewing the key facts of the case, said: “The provenance of this shawl is questionable as the DNA results are not primary but secondary. That means the profiles obtained could match any one of 400,000 people in 1888.

“Sotheby’s did some tests on this shawl and they believed it to be Edwardian, not Victorian.

“Their basic analysis confirmed the material came from the early 1900s – which is at least 12 years after the murder of Catherine Eddowes.

“It is not really a shawl either, as it is about 8ft long. And, as it has been handled by countless people over the years, it is likely to be cross-contaminated.

“Discredit the shawl and the rest is ­academic because the DNA results are not conclusive.

“There are still lots of questions to be answered over this material.”

The claims Kosminski was the real Ripper were made by ­author ­Russell ­Edwards, who bought Eddowes’ blood-stained shawl at ­auction in 2007. A police officer claimed to have taken it from the scene of the murder and said it was then handed down through his family.

“Marriott says he believes the real Ripper may have been responsible for another 17 slayings”

Edwards had it tested by expert Dr Jari Louhelainen, who found DNA matches to descendants of the suspect and Eddowes.

But Mike Covell, who has also published several books about the Ripper murders, rubbished the claims too.

He said: “The history of the blood-stained shawl is hazy to say the least. Although Kosminski was named by police as a possible suspect, experts on the case have long ruled him out as a serious contender to be the Ripper.

“A police officer named Amos Simpson claims to have not only been at the murder scene but to have taken the shawl home. This is false – he was never at the scene.”

The historian also says Kosminski was considered a harmless mentally ill man who was locked up because he had a ­“fondness for masturbation”. He died in an asylum from gangrene aged 53.

Former detective Marriott says he believes the real Ripper may have been responsible for another 17 slayings.

He reckons the Ripper was a German sailor Carl Feigenbaum, who worked on a ship carrying freight between Germany, New York and London.

He says he can link other ­Ripper-style murders in Germany and America to Feigenbaum, who was later convicted and executed at New York State’s Sing Sing prison after murdering his landlady in Manhattan in 1894.

The Ripper carried out the grisly murders of at least five prostitutes in 1888.‘Sotheby’s had tested the shawl and believed it to be Edwardian not Victorian’